Kidney Modelling for FDG Excretion with PET

The purpose of this study was to detect the physiological process of FDG's filtration from blood to urine and to establish a mathematical model to describe the process. Dynamic positron emission tomography scan for FDG was performed on seven normal volunteers. The filtration process in kidney can be seen in the sequential images of each study. Variational distribution of FDG in kidney can be detected in dynamic data. According to the structure and function, kidney is divided into parenchyma and pelvis. A unidirectional three-compartment model is proposed to describe the renal function in FDG excretion. The time-activity curves that were picked up from the parenchyma, pelvis, and abdominal aorta were used to estimate the parameter of the model. The output of the model has fitted well with the original curve from dynamic data

Iliopsoas fibrosis after revision of total hip arthroplasty revealed by 68Ga-FAPI PET/CT: a case report

BackgroundTotal hip arthroplasty (THA) is a well-established surgical procedure that has been extensively validated to alleviate pain, enhance joint function, improve the ability to perform daily activities, and enhance overall quality of life. However, this procedure is associated with certain complications, among which skeletal muscle fibrosis is a frequently overlooked but significant complication that can lead to persistent pain. Currently, there is no effective method for diagnosing skeletal muscle fibrosis following total hip arthroplasty.Case reportWe report a 75-year-old male patient who complained of left groin pain after revision total hip arthroplasty. Serological examinations, X-rays, and bone scan results were all normal. However, during the 68Ga-FAPI PET/CT examination, we observed significant radiotracer uptake along the iliopsoas muscle. This abnormal uptake pattern suggested potential biological activity in this specific area. Combined with physical examination, the patient was diagnosed with iliopsoas fibrosis.ConclusionsThe presented images indicated that the uptake pattern was an important indicator for diagnosis, and the prospect of fibroblast activation protein in the diagnosis of skeletal muscle fibrosis has shown certain application value

Quantitative analysis of preferential utilization of AAV ITR as the packaging terminal signal

Genetic engineering advances have led to recombinant adeno-associated virus (rAAV) becoming an invaluable tool for the development of effective gene therapies. The production of rAAV is susceptible to off-target heterogeneous packaging, the effects of which are still being understood. Here, rAAV vectors with four-genome lengths were produced using both adherent and suspension HEK293 cells to understand the 5′ITR termination. AAV8 vectors were produced from the human FVIII plasmid for a full-length cargo of 4,707 nucleotides with specific truncations, creating smaller genomes. Conventionally, rAAV is characterized by differentiating empty capsids from full capsids, but for this work, that description is incomplete. The small genomes in this study were characterized by charge detection-mass spectrometry (CD-MS). Using CD-MS, packaged genomes in the range conventionally attributed to partials were resolved and quantified. In addition, alkaline gels and qPCR were used to assess the identity of the packaged genomes. Together, these results showed a propensity for unit-length genomes to be encapsidated. Packaged genomes occurred as replication intermediates emanating from the 5′ITR, indicating that HEK293 cells prefer unit-length genomes as opposed to the 5′ITR termination and heterogeneous DNA packaging observed previously from Sf9 cell systems. As both manufacturing processes are used and continually assessed to produce clinical material, such an understanding will benefit rAAV design for basic research and gene therapy

Performance characteristics of 18F–fluorodeoxyglucose in non-infected hip replacement

PurposeThe aim of this study was to retrospectively analyze 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/ computed tomography (CT) images of non-infected hip arthroplasty patients and summarize findings that may be useful for clinical practice.Methods18F-FDG PET/CT images of non-infected hip arthroplasty patients were collected from September 2009 to August 2021. The region of interest was independently delineated by two physicians and maximum standardized uptake values (SUVmax) were recorded and compared. Serologic data were also collected and the correlation between SUVmax and serologic parameters was analyzed, while the images were classified based on the 18F-FDG uptake pattern in the images using the diagnostic criteria proposed by Reinartz et al. (9). The interval between hip replacement and PET/CT was classified by year and the characteristics of the two groups were compared. The images of patients who underwent PET/CT multiple times were analyzed dynamically.ResultsA total of 121 examinations were included; six patients underwent PET/CT twice and two patients had three scans. There were no significant correlations between SUVmax and serologic results. The interobserver agreement between the two physicians in the classification according to the criteria of Reinartz et al. (9) was 0.957 (P < 0.005). Although there was non-specific uptake in cases with an arthroplasty-to-PET/CT interval this was non-significant. Additionally, 18F-FDG showed potential utility for dynamic observation of the condition of the hip.ConclusionSUVmax provided information independent of serologic results, meanwhile 18F-FDG showed potential applicability to the dynamic monitoring of hip arthroplasty-related diseases. However, the presence of blood vessels and muscles affected image interpretation and the specificity of 18F-FDG was not optimal. A more specific radionuclide is needed to maximize the benefits of using PET/CT for the assessment of periprosthetic joint infection (PJI)

Simple, Rapid and Reliable Preparation of [11C]-(+)-a-DTBZ of High Quality for Routine Applications

[11C]-(+)-a-DTBZ has been used as a marker of dopaminergic terminal densities in human striatum and expressed in islet beta cells in the pancreas. We aimed to establish a fully automated and simple procedure for the synthesis of [11C]-(+)-a-DTBZ for routine applications. [11C]-(+)-a-DTBZ was synthesized from a 9-hydroxy precursor in acetone and potassium hydroxide with [11C]-methyl triflate and was purified by solid phase extraction using a Vac tC-18 cartridge. Radiochemical yields based on [11C]-methyl triflate (corrected for decay) were 82.3% ± 3.6%, with a specific radioactivity of 60 GBq/mmol. Time elapsed was less than 20 min from end of bombardment to release of the product for quality control

Intelligent manufacturing security model based on improved blockchain

The Industrial Internet of Things (IIoT) plays an important role in the development of smart factories. However, the existing IIoT systems are prone to suffering from single points of failure and unable to provide stable service. Meanwhile, with the increase of node scale and network quantity, the maintenance cost presents to be higher. Such a disadvantage can be effectively compensated by the features such as security, privacy, non-tamperability and distributed deployment supported by the blockchain. In this paper, first, an intelligent manufacturing security model based on blockchain was proposed. Due to the high power consumption and low throughput of the traditional blockchain, IoT devices with limited power consumption can not work independently. Therefore, in this paper, a new Merkle Patricia tree (MPT) was adopted to extend the blockchain structure and provide fast query of node status. Second, since the MPT does not support concurrent operation and the data operation performance deteriorates with high data volume, a lock-free concurrent and cache-based Merkle Patricia tree was proposed (CMPT) to support lock-free concurrent data operation, which can improve the data operation efficiency in multi-core system. The experimental results indicate that, compared with the original MPT, the CMPT proposed in this paper effectively reduced the time complexity of data insertion and data query and improved the speed of block construction and data query

Does the novel integrated PET/MRI offer the same diagnostic performance as PET/CT for oncological indications?

BACKGROUND: We compared PET/MRI with PET/CT in terms of lesion detection and quantitative measurement to verify the feasibility of the novel integrated imaging modality for oncological applications. METHODOLOGY/PRINCIPAL FINDINGS: In total, 285 patients referred to our PET/CT center for oncological indications voluntarily participated in this same-day PET/CT and PET/MRI comparative study. PET/CT images were acquired and reconstructed following routine protocols, and then PET/MRI was performed at a mean time interval of 28±11 min (range 15-45 min). PET/MRI covered the body trunk with a sequence combination of transverse T1WI 3D-volumetric interpolated breath-hold, T2WI turbo spin echo with fat saturation, diffusion-weighted imaging with double b values (50 and 800 s/mm2), and simultaneous PET acquisition over 45 min/5 bed positions. The maximum standardized uptake value (SUVmax) was assessed by manually drawn regions of interest over fluorodeoxyglucose-positive lesions. Among 285 cases, 57 showed no abnormalities, and 368 lesions (278 malignant, 68 benign and 22 undetermined) were detected in 228 patients. When stand-alone modalities were evaluated, PET revealed 31 and 12 lesions missed by CT and MRI, respectively, and CT and MRI revealed 38 and 61 more lesions, respectively, than PET. Compared to CT, MRI detected 40 more lesions and missed 8. In the integrated mode, PET/CT correctly detected 6 lesions misdiagnosed by PET/MRI, but was false-negative in 30 cases that were detected by PET/MRI. The overall diagnosis did not differ between integrated PET/MRI and PET/CT. SUVmax for lesions were slightly higher from PET/MRI than PET/CT but correlated well (ρ = 0.85-0.91). CONCLUSIONS/SIGNIFICANCE: The novel integrated PET/MRI performed comparatively to PET/CT in lesion detection and quantitative measurements. PET from either scanner modality offered almost the same information despite differences in hardware. Further study is needed to explore features of integrated PET/MRI not addressed in this study